Envoy can enter an endless loop while decompressing Brotli data with extra input
Priority HIGH 72CWE-835Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- Partial Red Hat: 2 fixed, 1 without a fix
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat. Impact type from CWE-835.
Summary
Envoy is a cloud-native, open source edge and service proxy. Envoyproxy with a Brotli filter can get into an endless loop during decompression of Brotli data with extra input.
Why it matters now
Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00674 52nd percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix Partial Red Hat: 2 advisoriesRed Hat: 2 fixed, 1 without a fix
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- Poc
- Automatable
- Yes
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| envoyproxy | envoy | 1.30.0 – 1.30.1; 1.29.0 – 1.29.4; 1.28.0 – 1.28.3; > 1.18.0, <= 1.27.5 | — | No fix listed | CNA |
- envoy Vendorenvoyproxy Affected 1.30.0 – 1.30.1; 1.29.0 – 1.29.4; 1.28.0 – 1.28.3; > 1.18.0, <= 1.27.5 Fixed in — No fix listed CNA
CPE configurations NVD · 1
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:envoyproxy:envoy:*:*:*:*:*:*:*:* | 1.18.0 to before 1.27.6; 1.28.0 to before 1.28.4; 1.29.0 to before 1.29.5; 1.30.0 to before 1.30.2 | Vulnerable | envoyproxy |
- cpe:2.3:a:envoyproxy:envoy:*:*:*:*:*:*:*:* Versions 1.18.0 to before 1.27.6; 1.28.0 to before 1.28.4; 1.29.0 to before 1.29.5; 1.30.0 to before 1.30.2 Vulnerable ·envoyproxy
Remediation
Red Hat 2 advisories
- RHSA-2024:7725 Released 2024-10-07 · Red Hat rating ImportantRed Hat OpenShift Service Mesh Containers for 2.5.5
- RHOSSM 2.5 for RHEL 8 openshift-service-mesh/grafana-rhel8, openshift-service-mesh/istio-cni-rhel8, openshift-service-mesh/istio-must-gather-rhel8 +5
- RHSA-2024:7724 Released 2024-10-07 · Red Hat rating ImportantRed Hat OpenShift Service Mesh Containers for 2.4.11
- RHOSSM 2.4 for RHEL 8 openshift-service-mesh/grafana-rhel8, openshift-service-mesh/istio-cni-rhel8, openshift-service-mesh/istio-must-gather-rhel8 +4
Vendor assessments
Red Hat
Red Hat rating: Important. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| OpenShift Service Mesh 2 | Affected | No fix planned: Will not fix |
| RHOSSM 2.4 for RHEL 8 | Fixed | RHSA-2024:7724 |
| RHOSSM 2.5 for RHEL 8 | Fixed | RHSA-2024:7725 |
Timeline
- 2026-10-02 Threatist record created from CVE-2024-32976
- 2026-11-05 Affected versions changed · CNA
References
More envoyproxy Envoy vulnerabilities
- TI-2026-79288 Out-of-bounds write in Google Brotli decoder KEVCVSS 4.0CRITICAL 9.2
- TI-2023-23979 The HTTP/2 protocol allows a denial of service (server resource consumption) because… KEVCVSS 3.1HIGH 7.5
- TI-2024-20001 HTTP/2: CPU exhaustion due to CONTINUATION frame flood CVSS 3.1HIGH 7.5
- TI-2024-18524 HTTP/2: memory exhaustion due to CONTINUATION frame flood CVSS 3.1HIGH 7.5
- TI-2023-12215 Envoy client may fake the header `x-envoy-original-path` CVSS 3.1CRITICAL 9.1
- TI-2023-18002 Envoy vulnerable to OAuth2 credentials exploit with permanent validity CVSS 3.1CRITICAL 9.8
Sources
- CVE-2024-32976 · CVE Program
- CVE-2024-32976 · NVD
- FIRST EPSS
- CVE-2024-32976 · Red Hat security data · CC BY 4.0
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